1. Field of the Invention
The present invention relates to a refrigerant condenser comprised of a pair of headers connected by a plurality of tubes, through which tubes a refrigerant flows in a serpentine manner.
2. Description of the Related Art
In the past, as this type of refrigerant condenser, provision has been made of a multiflow (MF) type refrigerant condenser such as the one shown in FIG. 8. That is, a pair of headers 1 and 2 are connected by a plurality of tubes 3 comprised of flat tubes. In the headers 1 and 2 are arranged separators at predetermined positions so that the refrigerant will flow in a serpentine manner through the tubes 3 between the headers 1 and 2.
In this case, to raise the heat exchange rate, Japanese Unexamined Patent Publication (Kokai) No. 63-161393 discloses a construction in which the number of times the refrigerant changes direction of flow in the headers 1 and 2 (hereinafter referred to as number of "turns") is set to one or more, while Japanese Unexamined Patent Publication (Kokai) No. 63-34466 discloses a construction in which the number of tubes making up the refrigerant passageway is reduced so as to reduce the cross-sectional area of the refrigerant passage from the inlet to the outlet.
In a refrigerant condenser comprised of a refrigerant passage which is turned back and forth as in the above-mentioned related art, however, if the number of turns of the refrigerant passage is increased to set the condensation distance large, while it is possible to increase the flow rate of the refrigerant and raise the heat exchange rate, the pressure loss inside the tubes increases, whereby the refrigerant pressure falls and along with this the problem arises of a fall in the condensation temperature. Therefore, when the number of turns of the refrigerant passage is set excessively large, the temperature difference between the outside air and the refrigerant becomes smaller, which is a factor behind a reduced heat exchange performance.
On the other hand, if the number of turns of the refrigerant passage is reduced to set the condensation distance smaller, while it is possible to decrease the pressure loss in the tubes, the flow rate of the refrigerant ends up falling, the heat exchange rate in the tubes becomes smaller, and the performance falls, which creates another problem. In view of the above, there assumingly is a number of turns of the refrigerant passage which is optimal for each heat exchanger.
The above-mentioned related art, however, merely suggest that increasing the number of turns or decreasing the sectional area of the passage contributes to an improved heat exchange rate. They do not go so far as to specify the optimal condensation distance for a heat exchanger and therefore do not solve the basic problem of improving the heat exchange rate.